ABSTRACT My overall goal is to advance the evidence needed to stem the opioid epidemic, and to translate the evidence into real-world implementation and effective public health policy. The current opioid epidemic in the US was driven by widespread use of prescription opioids (POs) for chronic pain. In response, guidelines and health policies increasingly promote use of opioid risk mitigation strategies such as PO tapering (reducing the dose or discontinuing POs). However, adoption of opioid risk mitigation strategies is outpacing the evidence, for example, outcomes of PO tapering and optimal strategies for implementing PO tapering in real-world HIV and primary care settings are unknown. PO tapering can have particularly serious implications for HIV control, if tapering causes patients to fall out of HIV care or replace POs with illicit or injected opioid use; but the risks have not been quantified and factors associated with these outcomes have not been described. Given the overall lack of evidence about PO risk mitigation strategies and their implementation and the urgency of addressing the epidemic, it is imperative to expand the capacity of clinician-investigators conducting patient- oriented research on PO use in HIV+ and HIV- individuals. I am a physician who treats chronic pain and opioid use disorder, an investigator focused on judicious PO prescribing for over a decade, and an educator with a strong mentoring track record and exceptional institutional resources to support mentees. This K24 mid-career investigator award will help to expand capacity of clinician investigators in the field by: 1) providing outstanding mentorship to junior investigators focused on PO use in chronic pain, 2) expanding my research in implementation science methodologies to optimize translating evidence into practice, and 3) advancing my development as a leader in translating evidence about PO use into guidelines and health policy. My strong existing research program focused on PO risk mitigation practices for HIV+ and HIV- patients with chronic pain, along with exceptional advisors and institutional resources, will provide a platform for mentoring and expanding my skills. Using my existing study cohorts and new primary data collection including qualitative interviews and a discrete choice experiment, we propose the following new research aims: 1) to examine the positive and negative outcomes of PO tapering among HIV+ and HIV- patients with chronic pain, and 2) to identify patient preferences for different PO tapering strategies among HIV+ and HIV- patients with chronic pain and high-risk PO use. All proposed research will be conducted with mentees and will provide ample opportunities for mentee development in diverse research methods, responsible conduct of research, and preparing manuscripts and grant applications. Findings from the research will inform future interventions and guidelines for PO tapering. Overall, the proposed plans for mentoring, career development, and research will expand capacity to address the opioid epidemic.